Joan, I am unsure which casino you are trying to download. RTG is just the software that a variety of casinos use.
However in most cases when a download is corrupted, for whatever reason it is best to remove it using the "Add/remove programs function on your Control Panel (click start and select control panel option).
Once you have removed the file try to upload it a second time.
Personally I recommend going to our
All online casino link and find the casino link you want.
it sometimes helps to close other programs that may be running in the background... (Not your antivirus, irregardless of what some may suggest)
hope this corrects it.